Changeable-compression engine.



E. THOMSON. GHANGEABLE COMPRESSION ENGINE. APPLICATION FILED SEPT. 11, 1907.

Patented June 27, 1911.

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Witnesses B. THOMSON.

'OHANGBABLE COMPRESSION ENGINE.

APPLICATION FILED SEPT.11, 1907.

996,378 Patented June 27,1911.

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Inventor:

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ELIHU THOMSON, OF SWAMPSCOIT, MASSACHUSETTS, ASSIGNOR T0 GENERAL ELECTRIC COMPANY, A CORPORATION OF NEW YORK.

CHANGEABLE-COMPRESSION ENGINE.

Specification of Letters Patent. p t t June 27, 1911 Application filed September 11, 1907. Serial No. 392,274.

To all whom it may concern:

Be it known that I, Emnn THOMSON, a citizen of the United States, residing at Swampscott, county of Essex, State of Massachusetts, have invented certain new and useful Improvements in Changeable-Cour pression Engines, of which'the. following is a specification.

This invention relates to engines operated by explosive vapor, and its object is to enable the compression space in the cylinder to be varied in size at will, and thus increase or lower the pressure to which the charge of explosive mixture is compressed. The principal reason for changing the compression is to adapt the engine to run with different fuels, such as kerosene, gasolene or alcohol, each of which requires a different degree of compression to give the highest efficiency. Moreover, an engine provided with means for changing the compression While running can be started at a low compression and run later at a high compression, a feature of importance where therunning compression is so high as to make it difficult to crank the engine by hand.

The invention also affords provision for running any length of time at a compression suitable for a given fuel, such as gasolene, and for changing quickly at any time .to operate with another fuel, such as alcohol.

Ordinarily, two degrees of compression Will be sufficient, although threeor even more may be provided for, if desired. In any event, the change is made without breaking the compression.

In the accompanying drawings, Figure 1 is a longitudinal section of-aninternal combustion engine embodying one mode of car rying out my invention, the parts being arranged for high compression; Fig. 2 is a top View of the same; and Fig. 3 is a longitudinal section of the cylinder with a somewhat modified construction of parts for varying the compression space.

The engine is shown as consisting of one or more cylinders 1, mounted on the usual crank case 2 containing the shaft 3 and crank or cranks 4 which can receive motion from the piston or pistons 5 through the connecting-rod or rods 6. Cam shafts 7 operate the bell-crank levers 8 by which movement is imparted to the valve-rods 9,

10; the former actuating the inlet valves and the latter the exhaust valves.

' Fig. 1 shows a double inlet valve, composed of two independent valves 11, 19, the former seating at the inner end of a bushing 13 inserted in the head of the cylinder, and the latter seating against a shoulder 11 near the outer end of said bushing; said outer end communicating with the intake pipe or conduit 97 by a lateral port 15. The stem 16 of the inner valved] is inclosed in the tubular stem 17 of the outer valve 12.

and the two stems pass up through the closed top of the lnishing. The stem 17 is secured to the actuating arm 18 on the valve-rod. but the stem 16 extends above said arm and carries at its upper end a flanged head 19. A helical conn rcssion spring 20 abuts be tween said head and the upper surface of the arm,and urges theinncr valve llagainst the lower end of the tubular stem 17. standard 21 rises from the top of the bushing, and at its upper end pivoted a can]- lever 22 which bears on the head 19 on the stem 16. IVhcn the cam lever is in the position shown in Fig. 1, both valves open and seat at the same time; but by turning the cam to the position shown in Fig. 3. the inner valve 11 will be forced down off its seat and held there, so that it cannot close, although the operation of the outer valve 1 is not interfered with.

In Fig. 1, with both valves seating, the inner one is the working valve, and the compression space that between the top of the piston and the under side of said valve, whereby high compression results. But, when the inner valve is forced down, the outer valve becomes the working one, and the space. inside .the' bushing between the two valves is added to the former compression space, so that a low compression is obtained. The space between the 'alves can be made of such size as to produce the variation of compression desired. If a still lower compression is wanted, the exhaust valve 2 controlling the flow from the cylinder to the exhaust pipe or conduit 28 may he made double, as shown in Fig. 3, in the same way that the inlet valve is constructed. This is not-necessary, however, unless more than two degrees of compression are desired. The inner valve, although it is within the explosion space when low compression is used, is not subject to overheating, because it is not struck by any powerful blast of gas, and moreover, it is cooled by every incoming charge of fresh minture.

It is evident that by means or my 1nvention the engine may be started with low compression, as for instance when using alcohol. as a fuel, and then for high eliiciency of action it may be quickly thrown, while running, into a condition of high compression. Th same engine may be run by gaselene with the inner valve permanently open; and in this case, should it be desired to start on still lowercompression, the inner exhaust valve 23 (Fig. can be opened, to be closed after the engine is running.

In accordance with the provisions of the patent statutes, I have described the principle of operation of my invention, together with the apparatus which I now consider to represent the best embodiment thereof; but I desire to have it understood that the apparatus shown is only illustrative, and that the invention can be carried out by other means.

What I claim as new and desire to secure by Letters Patentoi the United States, i

1. The combination with a cylinder of an internal combustion engine, of an auxiliary compression chamber communicating with the compression space of the cylinder, a. conduit, a valve controlling communication between the conduit and the chamber, means for actuating said valve, a second valve for connectingv the chamber with and disconnecting it from said space, a stem or spindle for the second valve that is mounted in the first valve for movement relative thereto, and a manually actuated device acting on said stem or spindle to open and close the second valve independently of the first valve.

2. The combination with a cylinder of an internal combustion engine, of a conduit, an auxiliary compression chamber communicating with the main compression space of the cylinder and with said conduit, a valve controlling communication between the conduit and the chamber, said valve having a tubular stem, means for actuating the valve, a second valve for connecting the chamber with and shutting it oil from said space, a. stem or spindle for the second valve that is mounted in said tubular stem, a spring acting, on the stem which tends to seat the second valve and shut off the chamber from said space, and a manually actuated cam for moving said stem or spindle in opposition to the spring to hold the second valve off its seat to cause the chamber to form part of the compression space and thereby vary the degree of compression.

3. The combination with a cylinder of an internal combustion engine, of an auxiliary chamber having inlet and outlet openings in save the walls thereof, one of which openings connnunicates with the compression space of the cylinder, a valve having plurality of members which are spaced apart along the same axis and control the openings of said chamber, said valve men'ibers opening in the same direction, and. means for moving one valve member rela tively to another and looking it in its adjusted position to cause the chamber to form or not to form a portion of the compression space of the cylinder.

4c. The combination with a cylinder of an internal combustion engine, of intake and exhaust conduits, auxiliary chambers having openings inthe walls thereof, one of which openings connects a given chamber with the interior of the cylinder and another open ing connects it with one of said conduits, double disk valves, each valve disk having its own seat adjacent one of the openings and opening toward the cylinder, means for actuating the valves to control the flow of tluid between the cylinder and the conduits, and means for holding the valve controlling the opening between a chamber and the cylinder oft its seat when it is desired to add said chamber to the compression space of the cylinder.

5. The combination with the cylinder of an internal combustion engine, of a conduit,

an auxiliary chamber having openings in the walls thereof one of which openings connects the chamber with the interior of the cylinder and the other with said conduit,

tions to control the How through the cham ber between the conduit and the cylinder,

and means for holding the valve controlling the opening between the chamber and the cylinder off its seat under other conditions to add said chamber to the compression space of the cylinder and to permit the other valve alone to control said flow.

6. The combination with a cylinder of an internal combustion engine, of an auxiliary chamber having inlet and outlet openings, one of which communicates with the compression space of the cylinder, a valve having a tubular stem, said valve controlling one of the openings, a second valve having its stem mounted in said tubular stem and controlling the other opening, means for adjusting the valves toward or away from each other to cause the chamber to form or not to form a part of the compression space of the cylinder, and means for operating the valves.

7. The combination with the cylinder of an internal combustion engine, of an auxiliary chamber having inlet and outlet openings, a valve rod, a valve having a tubular stern connected to the rod and controlling eeeeve v valve rod.

, 8. The combination with the cylinder of an internal combustion engine, of an auxiliary compression chamber having inlet and outlet openings one of which connects it with the compression space of the cylinder, a. valve rod, a valve having a tubular stem secured to the rod and controlling one of the openings, a second valve between the first valve and the cylinder having a stem passing through the tubular stem and controlling the other opening, seats for the valves formed in the walls of the chamber adjacent the openings, a spring holding the valves in position. to simultaneously close or open relatively to said seats, a manually controlled cam engaging with the upper end of the stem of the second valve to hold said valve off its seat to connect the chamber with said compression space without interfering with the operation of the other valve, and means for aotuatin the rod to cause one or both valves, according to the position of the cam, to control the flow of fluid through said chamber,

9. The combination with a cylinder of an internal combustion engine, of a conduit, I an auxiliary chamber having openings in the walls thereof communicating with the inte rior of the cylinder and with the conduit respectively, valves for controlling said openings, means for opening and closing the valves simultaneously under certain conditions to control the flow through the chamber between the cylinder and the conduit, and means for holding a valve controlling an opening between the chamber and the cylinder off its seat under other conditions to add said chamber to the compression space of said cylinder and to permit another of the valves to control said flow independently of the first-mentioned valve.

In witness whereof, I have hereunto set my hand this sixth day of September, 1907.

I ELIHU THOMSON. Witnesses:

JOHN A. MCMANUS, Jr., HENRY O. WESTENDARP. 

